Applications are subject to approval by Apple, as outlined in the SDK agreement, for basic reliability testing and other analysis. Applications may still be distributed if they are rejected, by the author manually submitting a request to Apple to license the application to individual iPhones, although Apple may withdraw the ability for authors to do this at a later date.
Applicants have been denied apps for fundamentally duplicating Apple apps, for example by providing an email interface with no added functionality or use or having the same elements as the built in SMS app. Applications have also been rejected for duplicating the functionality of iTunes. Applications may be rejected if they are of only "limited utility".Some reports indicate that toolbars must be placed at the bottom of the screen, and the vibration function should only be used for alerts.